Ventilator stacks or chimneys with canopies thereover are well known to the art, as may be seen from the below listed patents. The stack communicates with the air space underneath a roof and permits excessively heated and/or stale or polluted air to escape to the outside. The canopy is for the purpose of preventing rain and snow from falling back down the stack. Closures are often provided in order that the ventilating function may be lessened or stopped or, conversely, any backlash of the elements by way of wind or the like minimized. Typically, the canopy or hood will extend below the upper discharge edge of the stack or chimney for maximum protection.
However, in all of the previous designs, despite the presence of the canopy, or its configuration, or associated apparatus with the stack and canopy, effective weather proofing has not been achievable. It is most desired to keep the ventilating function constant, while deflecting or preventing flow back or blow under with respect to the canopy, rather than providing actual closure means. The latter malfunction eventually or break.
In gable mounted stacks with canopies, the impact of the atmospheric air, winds and air currents against the roof typically blows air up under the canopy. This may carry snow, hail, rain or the like, causing objectionable effects within the building. What is desired is a stack-canopy-other construction which will continuously maintain the ventilating function, while minimizing or preventing the many and varied negative effects of weather, particularly including snow, high wind, rain, hail and the like. To date this had not been achieved by others.